The relay modules MRxxxx round off the function module portfolio for connecting actuators and sensors of the MX-System. The relay modules MR1xxx allow direct switching of 230 V AC for lighting or fans, for example. The modules are also versatile due to the integrated digital I/Os. Three-phase asynchronous motors can be started directly with the mains voltage using the motor starter MR3xxx with up to 3 kW, or also operated in reversing mode. The control of a brake (24 V DC) and a thermal contact is possible with the modules and is provided in the connector. The solid-state modules MR4xxx can be used, for example, to operate electric heaters directly with the MX-System. Due to the integrated analog input channels, control can be realized without additional components. The MR1xxx and MR4xxx modules are designed with 3 channels. The MR3xxx motor starters, on the other hand, are designed as 1 or 2-channel variants. The modules of the MR series permanently monitor and digitize the phase currents. This makes it possible to detect overcurrents and switch off devices internally at an early stage accordingly. The integrated fuses meet the normative requirements for power protection and provide short-circuit protection.